1. EXTREME WEATHER:
Tornado clusters appearing more often, as seen through the lens of a 'tornado chaser'
Tornado chasers lead exciting lives. Greg Johnson was in a souped-up pickup tearing down the highway alongside Pilger, Neb., shooting a video of a tornado that was about to rip the town apart. He'd already seen the storm tear through the nearby Stanton area, and his team was hot on its trail.